Method of nonwoven cloth manufacture

ABSTRACT

A process for napped surface nonwoven web of interturned continuous filaments. Stretchable filaments are employed as starting material to form a web and various of the filaments are then forced through the web surface and stretched in the process to form loops on one surface of the web.

United States Patent l 13,579,763

[72] Inventor ReferencesCited UNITED STATES PATENTS 2/1962Glover.......................... 3,347,736 10/1967 Sissons....,.........

Francois Noel Sommer Paris, France [21] AppLNo. 633,073

X 2 7 oo 2 3,451,109 6/1969 Klein................. 3,484,283 12/1969Simpson et a1..........

[22] Filed Apr. 24, 1967 [45] Patented May 25, 1971 [73] Assignee SommerS. A.

[32] Priority Paris, France A r, 27, 1966 Primary Examiner-Louis K.Rimrodt France Attorney-Stevens, Davis, Miller and Mosher 59,330

[54] METHOD OF NON-WOVEN CLOTH MANUFACTURE ABSTRACT: A process fornapped surface nonwoven web of 14 Claims, 8 Drawing Figs.

intertumed continuous filaments. Stretchable filaments are employed asstarting material to form a web and various of the 28/722 D04h 18/00filaments are then forced through the web surface and 28/4, 72.2;stretched in the process to form loops on one surface of the web.

[51] [50] Field of I PATENTEI] lmzslsm SHEET 2 UF 2 METHOD OF NON-WOVENCLOTH MANUFACTURE The present invention relates to nonwoven fabrics,formed by a tangled mass of threads or fibers, having on one of theirfaces a tufted, hairy or looped appearance.

It has long been known to make felts of synthetic materials from tangledfibers or filaments consolidated by various means, of which the mostusual is needling.

There are thus obtained dense felts, relatively flat and firm and havingrough or sometimes fluffy surfaces, which, however, lack the qualitiesof softness of fur, for example, or of piled or looped materials used inthe manufacture of carpets.

Numerous processes are known for making nonwoven materials having such apiled or looped appearance and soft feel. In some methods there areforced through a suitable support, such as a cloth, felt, or paper, or afoam of plastic or rubber, continuous threads forming loops of which thetops can afterwards be cut and torn to produce hairlike fibers. Thethread is stitched through the support for example by machines calledtufting machines. This thread is expensive however since it must bequite free from faults. Further, tufting machines have a relatively slowoutput rate.

In other known processes, there are forced, through a support,discontinuous fibers providing a fibrous layer, by needling the fibersthrough the support. These discontinuous fibers come out of the surfaceof the support in the form of tufts of pile and it is thus the fibrousweb itself which produces them. There are obtained, in this manner,nonwoven needled cloths having a certain softness. It is even possibleto separate,

thereafter, the support and the fibrous web in order to obtain a needledpiled felt without intermediate support.

Finally, it has already been proposed to make a nonwoven piled materialby needling tufts of pile from a generating" web of discontinuous fibersthrough a foundation web also formed from tangled fibers.

The piled felts thus obtained are not very stable, however, because thefibers having free ends in a tuft of pile easily become detached fromthe needled web due to their short length. It is consequently necessaryto subject this kind of article to a complementary treatment in order toreinforce the adherence of the tufts of fiber to their generating web.

In order to eliminate this inconvenience it has been proposed to makepiled felts by using instead of discontinuous fibers, continuous strandsor filaments issuing directly from a tangled web of such fibers.

It is known, in effect, to make ordinary felts, consisting of amultitude of tangled continuous synthetic filaments previously stretchedin order to provide mechanical resistance, wherein cohesion is enhancedby needling. It is also known that this operation engenders asupplementary stretching of the filaments.

Among the advantages of these sorts of articles, it will be observedthat the formation of a felted web directly from continuous andpreviously stretched synthetic threads or filaments enables the usualoperations of crimping or cutting the filaments to be' omitted, thesebeing necessary only when using discontinuous fibers. Moreover, a feltedweb of drawn continuous filaments offers greater resistance to wear,since the filaments have a tearing resistance clearly superior to thatof discontinuous fibers.

However, experience shows that such webs do not lend themselves to theformation of tufts of filaments issuing from the web itself, which tuftsare for improving the external appearance and hand or feel of the web's.

This feature can be explained by the fact that the formation of longtufts by forcing the continuous filaments of a felted web through theweb itself by means of needles requires a deeper penetration of theneedles than in the case of a normal needling for simply reinforcing thecohesion in a web by orientating certain filaments perpendicularly tothe plane of the latter. The filaments thus deeply driven break before asatisfactory aesthetic effect is obtained on the web face from which theneedles protrude.

With respect to this prior art, the main object of the present inventionis to provide a new type of product, constituted by a nonwoven fabric,having the appearance of a carpet or fur, which can be simply andrapidly made, and combines the qualities of good mechanical strength,good resistance to wear, an aesthetic appearance and soft feel.

According to the present invention, a process for making a nonwovenfabric is characterized in that there is formed a web of syntheticsubstantially continuous filaments, incompletely stretched i.e.,possessing a certain capacity for further permanent elongation, and verytangled, and in that some of the filaments of this web are driventhrough the web itself and at the same time stretched, to cause them toprotrude in the form of loops from one of the faces of the web, thecapacity for initial permanent elongation of the filaments being chosenaccording to the depth to which the filaments are to be driven and thenumber of loops which it is desired to produce over a given surfacearea.

Another aspect of the invention is the realization of a needling devicefor penetrating a textile web guided by a movable support, said devicecomprising a movable head furnished with needles and a correspondingsupporting surface for the textile web provided with cavities oppositeto the needles, characterized in that the needles have a shaft with asmooth surface and at least two terminal points separated by a recess.

A further aspect of the invention in the realization of a nonwovenfabric having the appearance of a carpet or a fur, composed of at leastone web of tangled substantially continuous synthetic filaments,characterized in that the filaments of this web are orientated throughthe said web and form loops whose length is of the order of thethickness of the web, on at least one face of the latter.

It will be seen that in carrying out the invention, an agreeable effectcan be obtained by forcing loops of filaments through the web from whichthey extend, without however, neglecting to stretch as completely aspossible the filaments of this web in order that the finished productmay benefit from the favorable mechanical characteristics normal tostretched filaments.

The following detailed description of the invention is referred to theaccompanying drawings in which:

FIG. 1 is a graph showing the curve of elongation against pull which canbe obtained with a synthetic continuous filament;

FIG. 2 schematically illustrates a thread drawing apparatus;

FIGS. 3 and 4 show a needle according to the invention;

FIGS. 5 and 6 diagrammatically illustrate two variants of the fabricobtained according to the invention; and

FIGS. 7 and 8 diagrammatically illustrate two articles including afabric made in accordance with the invention.

When needling is carried out using barbed needles on any given web offibers, the needles produce, in a direction perpendicular to this web,tufts of fibers on the face of the web from which protrude the needlesas small lumps of fibers. There is obtained in this way a furtherconsiderable tangling of the fibers which constitute the base web,particularly on the face through which the needles enter which thusacquires a substantial cohesive strength. In contrast, the majority offibers initially in the lower parts of the web are only slightlysubjected to the action of the needles, and thus do not become asstrongly intertangled as the fibers in the upper surface, of which alarge part have been forced to penetrate through the mass of material.The surface at which the needles enter is therefore generally much moresolid than the exit surface which has often to be reinforced byimpregnations of plastic materials.

When, for any reason, and particularly aesthetic reasons, it is notdesired to thusly impregnate the needle exit face, one is faced with aweakness of this face of the material. It has been attempted tocompensate for this weakness by increasing the penetration of theneedles, i.e. by producing tufts or lumps of fibers of greater volume,but in this case, the fibers which appear in perpendicular position onthe surface, and even outside the surface, easily become detachedbecause the degree of their attachment to the material is insufficient.

It could thus be thought that it would be desirable to subject topenetration by needles a web composed of continuous filaments instead ofdiscontinuous filaments, the driven-out portions of the filaments, evenfrom deep within the web, being tightly attached to the latter by theirextensions. Tests have been carried out with known webs of continuousstretched filaments, but, it has been found that the action of a strongneedle penetration had the effect of rupturing the filaments before thedesired effect was obtained, these filaments being stretched by theneedles beyond their breaking point.

According to the present invention, it is proposed to drive filaments ofa web of nonstretched, or more exactly incompletely stretched filaments,through this web, in such a manner as to avoid breaking of thefilaments. Thus, further stretchability of the thread driven in the formof loops through the web is utilized in order to avoid reaching thebreaking point of the threads. The less the thread is stretched, themore the loop passing through the web can be elongated without breakingthereof.

However, in order more precisely to define the invention, it will bemore clearly stated what is intended by the expression incompletelystretched."

Synthetic threads such as for example polyamide, polyester, orpolypropilene, have the property, once solidified after the threadforming operation, of being capable of withstanding, without rupture butwith a modification of their structure, considerable degree of permanentelongation. This permanent elongation can be realized up to a limitwhich is more or less defined, beyond which the thread is said to bestretched and can hardly be elongated further and only elasticallybefore breaking. This stretched state, well known by specialists, andwhich results in an orientation of the molecules of the product is ingeneral sought and obtained industrially by an operation calleddrafting, because it is this which gives the thread its best mechanicalcharacteristics.

Several methods enable this state of a synthetic thread coming out ofthe spinneret to be determined, such as the study by X-rays of themolecules, carried out in the laboratory or the examination of astress-deformation graph which is used more easily in practice. Thismethod will be used here in order to characterize the state of a threadby the permanent elongation to which it can be subjected before arrivingat the stretched state.

The diagram of FIG. 1 represents the elongation up to breaking point ofa synthetic thread coming out of the spinneret as a function of thetension applied thereto. The tension t is shown as the ordinate and thelength l as the abscissa.

The part ab of the curve corresponds to the stretching phase proper,i.e. to the permanent deformation of the thread which is realized underpractically constant tension. The part be corresponds to an elasticdeformation, a property which it is easy to check by slackening off thetension from the point b: it will be seen that the relation ofdeformation to tension is shown by the straight line b'B. The part cdcorresponds to a permanent deformation preceding the breaking point withdestruction of the connections between the molecules, the diminution incross section and breaking of the filament occun'ng at d.

The capacity for permanent elongation of the filament will be definedhere by the ratio: AB/OB i.e. the ratio between the increase in lengthof the initial filament without tension and the length of the stretchedfilament without tension. The determination of this capacity forpermanent elongation is made easy by the presence of the elastic zonebe; in effect, the pull exerted to effect stretching can be largelyindeterminate provided it is situated in this zone.

The extend of the variation AB/OB depends essentially on the polymer andon the manner in which it is stretched. For nylon 6 for example, ofrelative viscosity 2, 8, this value can vary from 0.80 to as a functionof the conditions existing when the filament was made.

Thus, by incompletely stretched" is meant the state of a filament ofwhich the capacity for permanent elongation is other than zero. I

The possession of a simple manner of determination of this capacity forpermanent elongation enables the initial value for filaments used in themanufacture of textile material to be regulated; it is possiblethereafter to determine experimentally to what depth filaments can bedriven through the web in order that a certain percentage of thefilaments have a capacity for permanent elongation after the operationas close to zero as possible, that is to say practically stretched.

Many different methods of regulating the initial state of the filament,i.e., the value of its capacity for permanent elongation can be used. Itis possible, for example, to use well-known drafting frames, of whichthe speeds are regulated experimentally to obtain the desired capacityfor permanent elongation.

Such a regulation can also be performed at the outlet if the spinnerets,where the filament is formed from melted polymer. At the spinneretoutlet the threads are cooled, all the threads of a same spinneret beingdrawn at high speed by a takeup machine, or by a blowing nozzle fed bycompressed air. The drawing means are located at a considerable distancefrom the spinneret so that the threads do not stick together in theplastic state, and form what is called a multiple thread.

The term spinning ratio refers to the ratio between the driving speed ofthe thread and the speed of flow of liquid polymer though one of theholes of the spinneret. In practice, the drawing speed of the thread isalways much greater than the flow speed of the liquid into a hole of thespinneret, and this results in a considerable narrowing of the threadwhile it is being drawn in the plastic state.

This narrowing is accompanied by a modification of the structure as isshown in the following table resulting from experimental measurementswhich illustrate a correlation between the spinning ratio and thecapacity for permanent elongation Delta However, for a determineddiameter of the hole of the spinneret, the spinning ratio fixes the sizeor the denier of the thread. The capacity for permanent elongationcannot, therefore, be completely regulated by varying the spinningratio.

In order to diminish the stretching capacity beyond fixed limits withrespect to the thread forming, and independently of the size of thethread, the latter being the size at point A in FIG. 1, that is to saywithout tension on the bobbin or in the receiving can, the followingexpedient may be used: a thread stretching device is placed on thethread between the spinneret 1 and the drawing device 2 placed in aposition where the threads 3 of the multiple filament 4 are still hotbut no longer sticky, in such a manner as to perform the stretchingunder optimum conditions. An example of an embodiment of this threadstretching device, shown in FIG. 2, consists of two deflecting pulleys 5and 6 and an intermediate pulley 7 to which is applied a braking coupleof which the value is a function of the elongation which it is desiredto produce in the thread between these pulleys and the drawing machine.

For example, in the case of a spinning ratio equal to 56, the capacityfor permanent elongation can be varied by varying the speed of thestretching device, without changing the final denier value. By using theratio V/Vl of the winding speed to the speed of the pulley 7 of thestretching device, there are obtained experimentally capacities forpermanent elongation specified in the table hereunder:

AB/OB 0. 70

When the drawing device is a blowing nozzle, it is possible to cause thecapacity for permanent elongation to vary not only by means ofdeflecting rollers whose speed is maintained constant, but also byregulating the air pressure in the blowing tube in such a way that itproduces an elongation of the thread between the entry and the exit ofthe said blowing nozzle Example: starting with a spinneret having 200holes discharging 280 g./m. of polyamide 6, a multiple filament wasproduced which was blown in a blowing nozzle fed by compressed air at 6kg./cm.2 and placed at 1.80 m. below the spinneret. The speed of thethread at the exit of the blowing nozzle was in the region of 4.200m./mn and the size of the thread discharged without tension about 3deniers. The capacity for permanent elongation of the threads of themultiple filament was 0.080.

Finally, it is possible to make directly at the exit of the spinneret, amultiple filament collected by a suitable device, and of which thedenier (total and by thread) as well as the capacity for permanentelongation AB/OB are fixed in advance. Thereafter, in order to carry outthe invention there is formed, with the multiple filaments of which thecapacity for permanent elongation and also the denier are known, ahomogeneous web, having substantially constant apparent density andthickness and of which all the elementary filaments are tangled to avery high degree, so as to give the web a certain coherence.

Methods for forming such a web already exist in both the glass fiber andartificial textile industries. Generally speaking, these webs can beobtained from distributors of individual filaments or multiple filamentsdischarging the thread onto an endless receiving table which moves at aspeed clearly less than that at which the thread arrived thereon.Auxiliary devices for blowing air and for reciprocally driving thedistributors transversally with respect to the receiving table enablethe tangling of the threads to be increased.

All the parameters such as the composition of the multiple threads, thespeed of latter, the speed of the receiving table, the spacing betweenthe distributing devices are determined experimentally with a view toobtaining a regular web of material whose weight per square meterisknown in advance.

This web lacks cohesion however, and in order to reinforce the latter,the web is caused to pass, at the exit of the table on which it isforced, into a well-known needle loom having barbed needles. Thisneedling, being of relatively low density and low depth in order toavoid stretching the threads subjected to the action of the needles, isprincipally intended to facilitate the transport of the said web, or toenable it to be attached to one or more other webs according torequirements. The presence of a-lubricant or pulverized preparation, atthe entrance to the needle loom facilitates this operation.

According to the invention, an attractive effect is sought by' forcingloops of filaments through this web, without however neglecting tostretch the filaments of this web as completely as possible in order toobtain a finished product which benefits from the excellent mechanicalcharacteristics of stretched filaments.

To this end, the web is subjected to a very deep needle penetrationwhich causes the filaments of the web to be driven through the webitself, and at the same time stretches them.

The portions of the filaments which are pushed by the needling throughthe web, will be more stretched than those which remain implanted in theweb. It is, however, possible to provide an apparatus and a method tocarry out this operation wherein such a high percentage of the filamentsare completements, with such loops being of uncertain height and havinga very variablenurnber of strands. V

In order to obtain loops of presentable appearance, regularly formed, itis desiiable to always drive the same quantity of threads through theweb, and always to the same depth for a given adjustment of the machine.For this reason, it is preferable to use special needles as representedin FIGS. 3 and 4. Each has a shaft 8 having a smooth surface,terminating in two parallel pointed portions 9 and separated by a recess10 which pulls the filaments during its passage through the web andstretches them, the filaments remaining in the form of loops when theneedle is pulled out. By virtue of these needles, the filaments fonnloops, which are all at the same height, and have substantially the samenumber of strands.

These needles can be placed in a known needle loom in a single row. inone embodiment, they have a diameter in the order of 3 mm. and theirdistance from axis to axis is in the order of 5 mm, this distancenaturally being variable according to the effect which is desired.

The supporting plate of the needle loom, that is to say the aperturedplate on which rests the web and which serves to support it at themoment when the needles of the needling head penetrate it, canadvantageously have, instead of holes opposite each needle,longitudinally disposed slots, in order to facilitate advancing the web.

The advancement of the web takes place in steps in a rhythm which is instep with the movement of the needles and at a rate which is controlledby a governing roller at the exit of the machine for the spacing of therows of loops. In general, the latter is of the same order as thedistance between two neighboring loops of a same transversal row. Thusfor example, the needles were spaced apart two to the centimeter and theadvancement of the machine is adjusted to 6 mm. at a time.

However, and this applies especially when the distance between twoneighboring rolls is small, it is observed that the operation of forminga row of loops has a tendency to destroy the preceding row because ofslipping of the filaments in the web. In order to avoid this phenomenon,in the case in which it is consideredza nuisance, it is advantageous toneedle the web with the aid of two or more transverse rows of alignedneedles, the spacing of which corresponds to the rate of advancement ofthe needle loom.

Thus, the use of several rows of needles enables not only the portionsof filaments constituting the loops to be stretched,

.but also the trapping of those which remain between two loops.

Moreover, when several rows of needles are used, and when it is desiredto make very high loops, it is advantageous to locate the rows ofneedles according to the heights which increase in the direction of themovements of the web, each row thus effecting a part of the stretchingand of the formation of a same loop. There is obtained in this way arelatively progressive stretching of the threads.

Another method of forming the loops consists in using a cylinderprovided with needles according to the invention over the whole of itsperiphery, and to pass the web between this cylinder and a countercylinder having circular channels opposite each row of needles. Thismethod has the advantage of providing a slow rate of penetration of theneedles into the web, and of ensuring aprogressive and regularstretching of the filaments.

Before commencing the operation of forming the loops, it is advantageousto heat the web to the optimal stretching temperature, which temperaturedepends upon the polymer. Thus, for example, with polyamide 6, the loopscan be formed at a temperature of to C., and this greatly facilitatesthe operation of the machine, and provides fuller and more abundantloops, due to a diminution in the number of broken filaments. Thisheating can be effected by infrared radiation or by passage of the webthrough a heating tunnel. in certain cases, the penetration of theneedles is facilitated when a lubricating agent is sprayed onto the websince this favors slippingbetween the threads, and avoids threadbreakages, as is well-known practice in the needling technique.

The web 11 thus treated has on one of its faces, thick loops 12 ofvihich the height can be adjusted within a large range of values, andwhich can be clearly greater than 1 cm. (see FIG. 5).

Practically all the filaments are stretched for the reasons explainedabove, provided, of course, that the initial capacity for permanentelongation of the filaments of the web has been appropriately chosen asa function of the height and spacing of the loops which it is desired toobtain, this being easy to determine in an empirical manner.

Moreover, the presence of a zone of elastic deformation after this zoneof permanent deformation allows a certain latitude in the adjustment forthis initial capacity for permanent elongation of the filaments, so thatafter penetration by the needles the threads are stretched or nearly so.

It will be observed, however, that in the present invention, thiscapacity for initial permanent elongation has great importance,particularly for the length of the loops.

Thus, in order to obtain loops having a height of l mm. from a web of500 grams per square meter of filaments whose capacity for permanentelongation AB/OB was 0.65, was used. This web was caused to pass througha needle loom having three rows of needles, each row having two needlesper cen timeter of width, the rows being spaced from one another by 6mm. The penetration of the needles was adjusted in such a way that thelowest point of their movement was situated at 10 mm. below the surfaceon which the web rested.

Loops having a height of mm. have also been made, from a web of 500grams per square meter having filaments of which the capacity forpermanent elongation AB/OB was 0.65. This web was passed into a needleloom having two rows of needles each row having one needle to thecentimeter of width, these rows being spaced one from the other by 10mm. The penetration of the needles was adjusted so that the lowest pointof their movement was located at 25 mm. below the supporting surface ofthe web.

Moreover, loops having a height of 5 mm. have been made from a web of300 gramsper square meter having filaments whose capacity for permanentelongation AB/OB was 0.50. This layer was passed through a needle loomhaving two rows of needles each row having two needles to the centimeterof width and the rows being spaced one from the other by 6 mm. Thepenetration of the needles was regulated so that the lower point oftheir movement was located at 5 mm. below the surface on which the webrested.

ln these three cases, after analyzing the final product it was observedthat at least 80 percent of the filaments had a capacity for permanentelongation in the neighborhood of zero.

According to an interesting variation of the invention, a capacity forinitial permanent elongation and a needle penetration were chosen suchthat the filaments constituting the loops were pulled, by thepenetration of the needles beyond their breaking point; breakage of thefilaments at the top of the loops was thus provoked, and a carpet withthe cut hairs or pile 14 having the appearance of a velvet was produced.The filaments thus broken in the loops nevertheless remain very solidlygripped in the web 13 from which they project without any furthertreatment being necessary.

For example, a pile carpet was made starting from a web of 300 grams persquare meter, constituted by filaments having a capacity for permanentelongation AB/OB of 0.50. The web was passed through a needle loomhaving three rows of needles, each row having two needles per centimeterof width, the rows being spaced from the other by 6 mm., and thepenetration of the needles being adjusted so that the lowest point oftheir movement was located at 22 mm. below the supporting surface of theweb. The finished product had a pile of an average height of 8 mm.

Everything which has just been described, for continuous filaments whichhave not been cut at the spinneret outlet. can be applied to long fibersadapted for the formation of a large number of loops, and, for thisreason, to act as truly continuous filaments.

The fabric resulting from the needling can very advantageously betreated with moist heat with a view to stabilizing the filaments. Thistreatment can be performed during the coloring or printing of the web,by means of steam or by water under pressure, or even in the absence ofany coloring operation at all, if the filaments were previously coloredthroughout their mass. This treatment, whilst fixing the colorants, alsoreinforces the cohesiveness of the fabric by causing the filaments tocontract slightly and stabilizes the crystalline structure of thepolymers. The filaments then acquire a better resistance, in particularin the zones where they are incompletely stretched.

Nevertheless, if the fabric is intended for heavy duty use, as forexample in floor coverings, it is advantageous to reinforce it and toimprove its dimensional stability with the aid of another web forming areinforcement and formed with continuous filaments made in the same wayas those of the fabric that is by previously being stretched with aratio AB/OB in the vicinity of zero.

The loops 16 of the web 15 of incompletely stretched filaments areforced through the web 17 of stretched threads (FIG. 7), after the twowebs have been slightly needled together. It is clearly possible tocarry out this operation continuously with the rest of the process bycausing two series of thread distributors, one fed by a stretched threadthe other by an incompletely stretched thread, to discharge onto thesame receiving table.

By way of example, a carpet of this kind has been made by employing aweb comprising continuous stretched filaments of nylon 66" of a weightper square meter of 300 grams, on which there was placed a web ofcontinuous incompletely stretched filaments of nylon 66 of a weight persquare meter of 550 grams, the two webs being slightly needled togetherand thereafter subjected to a needle penetration according to theinvention, certain filaments of incompletely stretched thread beingforced through the web of stretched thread.

It is surprising to find that excellent results can also be obtained byoperating on the two webs in the reverse direction, i.e. by causing theneedle to enter, according to the invention, the web 18 of stretchedfilaments to cause them to emerge as loops 19 on the opposite face ofthe web 20 of incompletely stretched filaments (FIG. 8). The resistanceand stability of a carpet obtained in this way are remarkable.

Finally, for certain applications of such an article composed of one orseveral webs, the reverse side is coated with a plastic orrubber'material. In the fabrics according to the invention, the reverseside is constituted by the entry face of the special needles describedabove and, by reason of their substantial diameter and of their form,these needles left in the web a series of holes. These holes are so manychannels in which the usual coating materials preferentially engage. Ifone tries to solidly fasten these materials to the web, it is observedthat they pass through the fabric by means of these holes and this isclearly undesirable and does not happen with traditional needle fabrics.

During the practice of the invention, it was found that it wasadvantageous to coat the reverse side side of the carpet with amechanically foamed plastisol of polyvinyl chloride. This foam, obtainedby mechanically beating the latex or the plastisol before coating andgelling is used preferably with other porous materials, the expansion ofwhich during gelling is caused by a chemical expanding agent whichdecomposes under the effect of heat; in effect a foam formed duringheating has the same fault as a noncellular coating: it finds its wayinto the channels left by the passage of the needles, forming hardvertical parts, in the thickness of the carpet.

On the contrary, the mechanically foamed materials penetrate theinterstices and channels, but subside during gelling without leavinghard parts in the channels.

The mechanically foamed material can be coated by means of a scraper ora cylinder and in a single or several applications. lf of sufficientthickness, it constitutes a comfortable undercoat, which reinforces thedimensional stability of the product and endows it with an excellentrubbing coefficient, which are advantageous qualities for a floorcovering.

Besides application to carpets, the fabric made according to theinvention can have numerous other applications either alone, or incomposite form, in combination with other webs, or in the form of acoating. Thus, it can be used for example for making wall coverings,blankets, household textiles such as fabrics for seats, or for curtains,clothing textiles for linings or overcoats, fabrics for slippers, andall other products having the appearance of a carpet or a fur.

Iclaim:

l. A process for making a nonwoven fabric comprising the steps of:forming-a tangled web of synthetic continuous filaments which areincompletely stretched and therefore possess a certain capacity forpermanent elongation; driving some of said filaments through said web soas. to form loops which protrude from a surface of said web, and at thesame time stretching said filaments which are driven through said web,the capacity for initial pennanent elongation of said filaments beingchosen according to the depth to which the filaments are to be drivenand the number of loops which it is desired to form over a given surfacearea.

2. The process of claim 1 wherein the filaments which form the loops arecompletely stretched.

3. The process of claim 1 in which the filaments which form the loopsare extended beyond their breaking point so that the loops are caused tobreak at their extremities.

4. The process of claim 1 wherein substantially the same number offilaments is driven through the web to substantially the same depth forthe fonnation of each loop.

5. The process of claim 1 in which said filaments driven through saidweb substantially protrude from said web.

6. The process of claim 1 wherein before the formation of the loops, theweb is heated to the optimum stretching temperature of the filaments ofthe synthetic material under consideration.

7. The process of claim 1 in which after the formation of the loops,'the'web is subjected to a humid heat treatment.

8. The process of claim 1 wherein the web of substantially continuousand tangled filaments is subjected to needling prior to the formation ofthe loops. 9. The process of claim 1 in which, in order to form theloops, a number of filaments driven through the web by penetrating theweb with needles so as to force the filaments through the web.

10.' The process of claim 9 wherein the web is passed through a needleloom so that each loop is subjected several times to the action of theneedles.

11. The process of claim 9 in which the web is passed between a rotatingcylinder provided on its periphery with needles, and a support surfacewhich is grooved in alignment with the rows of needles on the cylinder.

12. The process of claim 1 wherein a first web of substantiallycontinuous incompletely stretched filaments is attached to a second webof completely stretched filaments and that the assembly is subjected toa deep needle penetration, the first foamed plastic material which isallowed to gel.

2. The process of claim 1 wherein the filaments which form the loops arecompletely stretched.
 3. The process of claim 1 in which the filamentswhich form the loops are extended beyond their breaking point so thatthe loops are caused to break at their extremities.
 4. The process ofclaim 1 wherein substantially the same number of filaments is driventhrough the web to substantially the same depth for the formation ofeach loop.
 5. The process of claim 1 in which said filaments driventhrough said web substantially protrude from said web.
 6. The process ofclaim 1 wherein before the formation of the loops, the web is heated tothe optimum stretching temperature of the filaments of the syntheticmaterial under consideration.
 7. The process of claim 1 in which afterthe formation of the loops, the web is subjected to a humid heattreatment.
 8. The process of claim 1 wherein the web of substantiallycontinuous and tangled filaments is subjected to needling prior to theformation of the loops.
 9. The process of claim 1 in which, in order toform the loops, a number of filaments driven through the web bypenetrating the web with needles so as to force the filaments throughthe web.
 10. The process of claim 9 wherein the web is passed through aneedle loom so that each loop is subjected several times to the actionof the needles.
 11. The process of claim 9 in which the web is passedbetween a rotating cylinder provided on its periphery with needles, anda support surface which is grooved in alignment with the rows of needleson the cylinder.
 12. The process of claim 1 wherein a first web ofsubstantially continuous incompletely stretched filaments is attached toa second web of completely stretched filaments and that the assembly issubjected to a deep needle penetration, the first web being placed atthe side through which the needles enter.
 13. The process of claim 1 inwhich a first web of substantially continuous incompletely stretchedfilaments is attached to a second such web of completely stretchedfilaments and that the assembly is subjected to a deep needlepenetration, the second web being placed at the side through which theneedles enter.
 14. The process of claim 9 in which the face throughwhich the needles enter the fabric is coated with a mechanically foamedplastic material which is allowed to gel.